Duplex pump.



C. M. CHURCH.

DUPLEX PUMP.

APPLICATION FILED JULY 24, 1913.

Patented June 22, 1915.

3 SHEETS-SHEET 1.

13 21 o o o o o o o 0 Q o o o 1 714 6 o 3 19 & 22 4 4 A I INVENTOR is V ATTORNEY c. M. CHURCH.

DUPLEX PUMP.

APPLICATION FILED JULY 24, I913.

l 1 44,298. I Patented June 22, 1915' 3 SHEETS-SHEET 2.

fla l INVENTOR M yam 0. M. CHURCH.

DUPLEX PUMP. APPLICATION FILED JULY 24. I913.

Patented June 22, 1915.

3 5HEETSSHEET 3.

PIE-.1U- 64 Inventor:

witusses i pa UNITE srnrns rares- FFICE.

CLARENCE M. CHURCH, ARNOLD, PENNSYLVANIA.

DUPLEX PUMP.

Specification of Letters Patent.

Patented June 22, 1915.,

Application filed July 24, 1913. Serial No. 786,950.

To all whom it may concern Be it known that I, CLARENCE M. CHURCH,

'10 My invention relates to pumps and particularly to that class known as duplex pumps wherein two or more cylinders are operated by steam or other fluid for the purpose of operating the pumps, and the principal object of my invention 15 to improve upon pumps of this character.

My invention consists, generally stated, in the novel arrangement, construction and combination of parts as hereinafter more specifically set forth and described and particularlyvpointed out in the claims.

To enable others skilled in the art to which my invention appertains to construct,

' operate and use my improved pumps 1 will .,describe the same more fully referring to the, accompanying drawingsin which Figure l is a top plan view of a duplex pump embodying my invention... Fig. 2is a side elevation of the same showing one of the operating cylinders in section. Fig. 3

is an enlarged detail view of the valve device showing its operation in connection with one of the cylinders. Fig. 4 is a like view of the valve device showing its oper- 5 ation in connection with the other cylinder.

Fig. 5 is a detail view of the lost motion arrangement on one side of the pump. Fig. 6 is a like view on the other sidecf the pump. Fig. 7 is a view of the linkemployed. Fig. 8 is a side View of the con necting rod arranged for lost motion adjustment. Fig. 9 is a. view of an indicator card. Figs. 10 and 11 show a modified form of my device.

Like symbols of reference herein indicate like parts each of the figures of'the drawings.

As illustrated in the drawings A represents the usual approved form of duplex pump and while the one shown in Figs. 1

and 2 is of the single duplex type this style is shown merely to avoid the complications in the description and drawings as the pump may be of the compound duplex type haw ing low and high pressure cylinders or any number of cylinders desired according to the class of work, etc.

The pump shown in Figs. 1 and 2 has a pair of pump cylinders 1 and 2 which are located parallel and contain the ordinary pumping parts (not shown) which parts are operated by piston rods 3 and 4 respectivel y which extend into said cylinders from operating cylinders 5 and 6 located parallel at the other end of the pump A. Within the operating cylinders 5 and 6 are the, pistons 7 and 8 which are secured to the ends of the piston rods 3 and l respectively and are operated by the valves 9 and 10 respectively in the valve casings l1 and 12 located above the said operating cylinders.'

Considering Figssil and 3 of the drawings and the parts in the position shown the valvecasing 11 has the usual ports 13 and 13 for admitting operating fluid to the cylinder 5 and for allowing such fluid to exhaust through said ports and into an exhaust part I l formed in the upper wall 15 of said cylinder and in the \lower face of the valve 9. The valve 9 isprovided with a valve stem 16 lliolfieritnds outward from-the valve casingll and into. a slide bearing 17 on the rock shaft stand 18. This rock shaft stand 18 is supported between the cylinders 1 and 5 upon a suitable support 19 extending between said cylinders and carries a rock shaft 20 at its upper end and a rock shaft 21 at its lower end as later explained. At the one end of-the rock shaft 20 is a small rock arm '22 secured firmly thereto and pivotally connected at its outer end with a sleeve 23 on a connecting rod 24 which sleeve is slidably mounted on, said connecting rod in order to provide for lost motion as later explained. The rock arm 22 is also provided with small supporting arms 22 and 22 one on each side of the same as hereinafter ex-- explained. At the ends of they connecting rods 24; and 2S nearest to the valve casing- 11 is a link 29 which is pivotallyiconnected between the some while at a point substantially near the center of said link it is pivotally connected with the valve stem 16 as shown in Figs and 3.

extending outward therefrom and operating in a slide bearing 17 on the rock shaft stand 18 while said valve casing is provided with "the ports 30 and 30 for admitting operating fluid to the cylinder 6 and with the exhaust port 31 formed. in the-upper wall 32 of said cylinder and the lower face of the valve 10.'

The upper rock shaft is provided on this side of the rock shaft stand 18 with a long rock arm 33 which is pivotally secured to the said shaft at a point substantially near the end of the same while above said shaft a small arm 33 extends as later explained.

' The other end ofthe' long rock arm 33 is 20 pivotally connected to a cross-head 34 on the shaft 4 in order to rock said arm and the shaft 20 connecting the same when the shaft v4 is set in motion. The lower rock shaft 21 is providedon this side pf the rock shaft wand 18 with :1 small rock arm 35 which is firmly secured thereto and which is pivotally connected at its one end to a sleeve 36 on the connecting rod37. which sleeve is arranged to provide for lost motion as later explained. Extending out from the other end of the rock arm are supporting arms 38 and 38 which are hereinafter described. The small arm 33 is pivotally connected to sleeve 39 slidably mounted on a connecting rod 40 35 to provide for lost motion as hereinafter explained. A link 40 is pivotally connected at itsends with the connecting rods 37 and 40 and is connected at a point substantially near the centerof the same with the valve 4 stem 16 leading to thevalve 10 in the valve casing 12. r

The small supporting arms 22 and 22 are each provided with a pin 44 for fitting into a'slot 45 in a release rod 46 and said 45 release rod is pivotally connected to a block 47 which is substantially of the 'size of the lbst motion adjustment on the connecting rod 24 whilea plate 48 connects said block and fits over a rod 49 which has a head 49 -there- 50 on in order to provide for a spiral spring 50 around said rod between said plate and head.

.The small supporting arms 38 and 38 which extend above the small rock arm 35 lost motion adjustment .onthe connecting .2. rod 37 whilesa plate connects said block and fits over "a rod 56 which has 'a head 57 thereon in order to provide for a a spiral spring 58 around said rod between said plate and head.

The, connecting rods 24,-

are

provided with the sleeves 27,36 and 39.

respectively which are adapted to slide on said rods between-the nuts 59andsaid nuts In Fig. 4 the valve casing 12 is shown-with 5 the'valve 10 therein having a valvestem 16' can be adjusted to any'd'esiredfposition to regulate the lei'igth of the lost motion travel.

' The use-and operation of myimproved pump is as follows :--Considering the .Piston 7 in the position in which it"is shown'in i Fig. 2 and the valve 9 uncovering the port 13 so as to allow loperatingifluid such as steam to enter the cylinder 5 hehindthe -piston 7 the port 13 communicateswith tha exhaust port-1,4 so as to allow 'the fluidon the front of the said pistonto beeuliausted from said cylinder when said pier-6h moves forward. The steam or iother eperating fluid will .now cause the piston 7' to move forward in the cylinder 5 and: exhaust the fluid in front of the same through the orts '13 and 14'- and at the same time the p ston rod 3 carrying the cross-head 26 will draw the long rock arm 25 with it so as to rock' or slightly rotate the r0 :k shaft 21 carried in the rock shaft stand 18. This motion of the long rock'arm 25 w.ll slide the sleeve? 27 on the connecting rod 28 until said sleeve strikes the nuts 59 on said rod whereupon the said rod will be pushed toward the valve casing 11 so that the link 29 will also be pushed in the same direction which movement will operate the valve 9 by the connection between said link and the. valve stem 16. When the piston 7 has thus reached a certain point in'its course of travel the operation -abo e explained will have moved the valve to a position where the ports 13 and 13 will be closed and the operating fluid will then expandand complete the piston stroke while the fluid on the front of said piston will be compressed in order to form acushion for said piston thereby eliminating any need of cushion valves. During this operation the piston. 8 1n the cylinder 6 has been at the opposite end of said cylinder and when the rock shaft '21 rotates it will also operate the small rock arm 35 whereupon the supporting arm 38 will belowered in order to withdraw'th'e block 54 from between the sleeve 36 and nuts 59 and the supporting arm 38 will be raised and the block 54 lifted toward the opening between the nuts 59 on the'connesting-rod 37 and the sleeve 36 so that said sleeve will travel on the connecting rod'37.

until it strikes the said nuts 59, whereupon said blockwillfallinto place. 'When the.

the'first half of the stroke of the'lpiston' in the cylinder ,5 theIs'haft 21 still-continues to rotate so that upon the last, half sleeve 36 has reached this position durin willbe pushed forward by the connecting rod 37 in order to operate -:the valve 10 in the casing 12, and thus open the port .30 leading into the cylinder 6. -When thefoperating fluid thus enters the cylinder 6. behind the piston 8 such piston is moved toward the outer end of said cylinder and the shaft 4 connecting the same pulls the long rock arm 33 toward thevalve casing, 12 which motion will rock or slightly rotate the shaft 20 carried at the upper end ofthe rock shaft stand 18. When the rock arm 33 thus operates on the shatt 20 the small arm 33 will move the sleeve 39 backward until it strikes the nuts 59 on the connecting'rod 40 which will consume the same amount of time asit takes the piston 8 to reach about the center of the cylinder 6. The block 5t carried'on the release rod 53' is now located between the end of the sleeve 36 and the nuts 59 farthest from the valve casing 12 so that when the lost motion has been taken up on the connecting rod 40 the piston 8 will be at about the center of the stroke, whereupon the connecting rod 40 will pull the link 40* with it and since the connecting rod 37 cannot be moved on account of. the position of the block 54; carried by the supporting arm 38 such link will operate the valve stem 10 and draw the valve 10-over the port 30 and 30 to close the same. The operating fluid in the cylinder 6 will then expand andcomplete the stroke of the piston 8 while the operating fluid on the other side of the said piston will be compressed on account of the port 30 being closed by the valve 10 and such compressed fluid will act as a cushion to prevent any jar of the piston or other operating parts. During this operation of the valve 10 the shaft 20 has operated the small rock arm 22 on the other side of the rock shaft stand 18 and as such arm turnstoward the valve' casing 12 the supporting arm 22 is raised so as to lift the block 47 out from between the nuts when the piston 8 in the cylinder 6 starts to complete its stroke the connecting rod 24 "is moved by the rotation of the shaft 20 so as to operate the link 29 which in turn operates the valve stem 16 and valve 9 and thus opens the port 13 leading-to the cylinder 5 from the valve casing 11 and opens the port 13 leading to the exhaust port 14.

This operation will cause the piston 7 to move in the cylinder 5 and the piston rod 3 willop erate the long rock arm 25 which will turn the shaft21 in order to take up the lost motion on the connecting rod'28 by the connection of said arm with the sleeve When the piston 7 has reached about the 29 is pushed backward at its lower end and since the sleeve 23 on the connecting rod 24 is at the end nearest the valve casing 11 and the block 47 carried by the supporting arm 22 is between the sleeve 23 and nut 59 g on the connecting rod 24: the link 29 will be operated or pivoted on the connecting rod 24 and thus operate the valve stem 16 and close, the ports 13 and 13 so that the newly admitted operating fluid will expand and the fluid still remaining on the other side of the piston 7 will be compressed in order to form a cushion for said piston 'to prevent any jarring of the working parts. During the last operation-and when the piston 7 in the cylinder 5 had started to travel in said cylinder the rotation of the shaft 21 which commenced at this point also rotated the small rock arm 35 on the opposite side of the rock shaft stand 18 and raised the block 54 carried by the supporting arm 38-and the sleeve 36 on the connecting rod 37 was moved along said rod until it reached the nut 59 whereupon the block 54: carried by the supporting arm 38 dropped between the said sleeve and nut 59 on said rod. This operation consumed the same amount of time asit took the piston 7 in the cylinder 5 to travel about half its stroke and during the last half of such stroke, the shaft 21 still revolving, the connecting rod '37 is forced backward thereby drawing the link 40 away from the valve casing 12 and thus operating the valve 10 through the valve stem 16 in order to open the port 30 and the port 30 and allow the piston 6 to travel forward in said cylinder. The apparatus used for blocking the lost motion on the connecting rods 24, 28, 37 and 40 can be omitted by using lost motion in the valve stems or by using a greater amount of steam lap in new pumps and the device shown would ordinarily not be used except where old pumps having practically no steam lap or lost motion on were being equipped with my impi-o. ed cutoff method.

Figs. 1.0 and 11 show a modified form of the device in which the links 29 and 40 are supplemented by a curved link 60 which has a slot (31 in the center of the same for engaging with a pin- 62 in the valve stems 16. and 16 and an extens'ion 63 above its connection with the connecting rods 24 and 40 for pivotally' connecting with a small link G l. The rock shaft stand 18 is pro vided with an extension 65 'for pivotally supporting a governing rod 66 which is also pivotally connected to the small-link 64 at its one end and carried a counterweight 67 at its other end while between the extensionct and said counterweight the said rod a valve cured while an arm 71 is also firmly secured to said shaft and extends to and is connected to the governor or mason regulator 72 so that said arm will be moved up and down according to the position of the regulator. l/Vhen the arm '11 is thus moved the shaft 70 will be rotated in the bearings 69 and the governing rod 66 either raised or lowcred so as to move the curved link 60 on the pin 62 of the valve stems 1 6 and 16". This regulation'will control the actual cut off in the valves 9 and 10 so that the regulator of the pumpor engine will supply the necessary cut as the engine needs it.

It will readily be seen that with my improved pump, the cut-off can be obtained at any desired point in the piston stroke and there will be an increased efficiency by reason of the same as is shown in Fig. 8 of the drawings. In this figure the ordinary steam pump indicator card is shown in dotted lines while the indicator card obtained from the same pump being equipped with my improved. dcvice is shown in full lines. In the old card shown in dotted lines 5 indicates the admission line while in the new card shown in full lines the admission is uniform and is indicated at a while the expansion is shown at c.

' Various modifications and changes in the design, construction and operation of my improved pump may be resorted to without departing from the spirit of the invention or sacrificing any of its advantages.

WVhat I claim as my inventionanddesire to secure by Letters Patent is l. A duplex pump comprising a pair of cylinders each having a piston therein con- I nected to a piston rod, valves controlling the cylinders each having a piston therein .con-

, nccted to a piston rod, valves controlling the operation of said pistons and having valve stems connected thereto, a pair of shafts rotatahly mounted with one connected to each of said piston rods bya rock arm, arms extending from each end of said'shaft and connected. to a sleeve slidable on a connecting rod in order to provide for lost motion, movable means for limiting the distance traveled by the sleeve and a link connected mechanism including a pa of between {each pair of said connecting rods and connected to the respective valve stems to regulate theoperating fluid cut-off in said cylinders. Y x 3. Theeombination -with-a duplex; pump having a pair of cylinder pistons therein, piston rods for the pistons, valves controlhug the operation of the pistons, and valve stems for the valves, of a valve operating mechanism 'includina a pair of shafts a pair of rock arms connecting theterminals of one shaft to each piston rod, linkspivoted to the I valve stems, connecting rods freely connected to the links, means slidable upon the hon necting rods for pivotally. connecting the rock arms and one of said shafts thereto, and movable means controlled. by the said shafts for limiting the sliding movement of the last mentioned means.

4. The combination with a duplex pump having a pair of cylinder pistons therein, piston rods for the pistons, 'valvescontroh ling the operation of the pistons, and valve stems for the valves, of af-valve;operating I I v rotatable shafts, a pair of rock armsactuated by the piston rods and keyed to the'sh'afts at opposite ends thereof, each of said arms being free withrespect to one shaft, a link carried by each piston rod, a connecting rod pivoted to each end of each link, 'a sleeve slidable upon each connecting rod, and means pivotally connectmg certain of. said sleevesto the rock arms and certain other of saidsleeves to the shafts.

5. The combination witha duplex pump havmg a pair of cylinder: pistons therein,

piston rods for the pistons, valves controlling the operation of the pistons, and valve stems for the valves, of-a valve operating mechanism including a pair of rotatable shafts, a pair'of rock arms actuated'by the piston rods and keyed to the shafts-at opposite ends thereof, each of said arms being free with respect to one shaft, a link carried by each piston rod, a connecting rod pivoted to each end of each-link,v a sleeve slidable upon each connecting rod, means pivotally connecting cerfiai of: sleeves to rock arms and certain other of said sleeves to'the shafts, and stop members movable tof-position against the connecting rodsfor limiting the movement of the sleeves thereon. i l

6. The-combination with a duplex-iipump' having a pair of cylinder pistons therein, piston rods for the'pistons, valves controlling the operation Ofthfi' pistons, and4-va'lve stems for the valves, ;o'- ,valve operating mechanism inchiding a air of rotatable" shafts, a pair of rock arms actuated ,by' the piston rods and keyed to therjjshaftsat ,opposite vends thereof, each of'said arms being free with respect to one shaft, "a l nk'carried by each piston rod, fijconnectingrod pivoted to each end of eachjlink, a=: sleeve slidable igs upon each connecting rod, means pivotally connecting certain of said sleeves to rock rms and certain other of said sleeves to the shafts, stop members movable to position against the connecting rods for'li'mitingthe movement of the sleeves thereon, and means movable With Said shafts for automatically controlling the position of the stop members.

7. The combination with a duplex pump having a pair of cylinder pistons therein, piston rods for the pistons, valves controlling the operation of the pistons, and valve stems "for the valves, of a valve operating mechanism including a pair of rotatable" shafts, a pair of rock arms actuated by the piston rods and keyed to the shafts at opposite ends thereof, each of said arms being free with respect to one shaft, a link carried by each piston rod, a connecting rod pivoted to each end of each link, a sleeve slidable Coplee o! thil patent may be obtained to! five cents each, by addressing the Commissioner of Intent,

uponeach connecting rod, means pivotally connecting certain, of said sleeves to rock arms and certain other of said sleeves to theshafts, stop members movable to position. against'the connecting rods for limiting the movement of the sleeves thereon, yieldable means normally holding said stop members in engagement with the connecting rods and sleeves, and means movable with the shafts CLARENCE M. CHURCH.

Witnesses:

T. B. HUMPHRIES, J. N. COOKE.

Washington, D. (1. 

